Active button javascript

Question

Hello friends...I have created a little quiz in which I have added 3 questions with 4 button each ..I want whenever someone click on any button it will change to grey ..so it shows that it is selected.and also tried but failed please help
https://code.sololearn.com/WqIE9mKl859H/?ref=app

Answer 1

You are missing 6 closing div tags, that are causing you some problems.
Such as not displaying quiz cards one at a time the way you want, and all of the answer buttons becoming gray after one click.

You really need to add the closing div tags

Answer 2

https://code.sololearn.com/W52NQIi2NaXr/?ref=app
Only next buttons are not good

Answer 3

There can be used for example such as following function for selecting buttons. Unfortunatelly the code need to be corrected for right functioning.
document.body.addEventListener("click", event => {
if (event.target.nodeName == "BUTTON")
event.target.style.border = "4px white solid";
}
});

Answer 4

Not getting it.